Not to get tied up in what verbage I found in the decades of reading about T5's...eg the Boss reference especially with the 5556 G cars discussed here. Heavy duty Export Durability.....package" is a term that gets away from Mach 1 or Boss
Firstly would suggest that all that you read is not always correct. Export details, especially suspension, has always been difficult to find and I've found on original cars that there was not just one set up for all export cars - especially as the years went by
Do know the original rear springs are 5556G
Front sway is 7/8 with bushing brackets like on the right in attached photo
I can always look at the original spindles for their casting numbers
Strut rods are original but no numbers.
Shock tower caps and "export" braces are original
Export braces. Do you have the two part shock tower supports or the one piece export brace? If the two piece any additional brackets or reinforcements?
Thing the subject of when the car was built was asked earlier but didn't get a response - sorry if I missed it if it was answered.
If its early then looking at the spindles will likely just produce an expected - not Boss suspension but want to cover the bases.
Sway bar isn't the same as a Boss